Search Results (737)

The valorisation of textile wool waste through sustainable conversion technologies such as pyrolysis has gained increasing attention as an effective strategy to reduce textile waste, recover valuable resources, and support the transition toward a circular economy. Herein, we investigated the pyrolysis of processed wool textile waste in CO₂ and N₂ atmospheres to recover valuable products and reduce the environmental impact. Key factors such as the temperature, carrier gas type, feed size, condensation set-up, and reactor configuration were evaluated for their influence on product distribution and quality. Pyrolysis at 900 °C in the presence of CO₂ led to greater gas formation (79 wt%), enhanced the stability and BET surface area of the char (10–12 wt%), and increased byproducts including phenol and indole in the bio-oil (13 wt%) product. CO made up over 65% of the gas at 900 °C due to the prevalence of the reverse (endothermic) Boudouard reaction, with the remnant gas made of CO₂ (21%) and small amounts of NH₃ (2%), HCN (0.8%) and SO₂ (0.3%). This CO-rich gas could have industrial applications such as Fischer–Tropsch after conditioning and N/S removal. Moreover, the higher carbon content (82.5% at 900 °C) increased the stability of char produced with CO₂ (compared to N₂), making it suitable for soil enhancement (~10% N at 900 °C) or pollutant removal and allowing it to be categorised and marketed as biochar. Despite low-temperature pyrolysis (350 °C) not being efficient in decomposing the whole wool waste, a staged pyrolysis with an initial low-temperature stage was shown to be effective in separately removing bromine-rich compounds. In summary, this study provides insights into the thermal decomposition behaviour of wool and the influence of the reaction conditions and reactor type on product distribution. Full article

Biochar has attracted increasing attention as a low-cost catalyst for biomass pyrolysis due to its developed pore structure, abundant surface functional groups and tunable physicochemical properties. In this study, biochars loaded with alkali and alkaline earth metal (AAEM) species were prepared by pyrolyzing cellulose impregnated with different chloride and acetate salts, including NaCl, KCl, CaCl₂, MgCl₂, CH₃COONa, CH₃COOK, (CH₃COO)₂Ca and (CH₃COO)₂Mg. The resulting AAEM-loaded biochars were subsequently employed as catalysts for cellulose pyrolysis to investigate their effects on product distribution, particularly levoglucosan (LG) and levoglucosenone (LGO) formation. SEM and XRD analyses revealed that the AAEM precursor significantly affected the morphology and phase composition of the biochars. Chloride-derived biochars retained crystalline salt phases or formed corresponding metal oxides, whereas acetate-derived biochars exhibited more dispersed metal-containing species. The introduction of AAEM-loaded biochars generally decreased bio-oil and LG yields while increasing char production, indicating enhanced secondary cracking and repolymerization reactions. Among the investigated catalysts, alkali metal-loaded biochars exhibited stronger inhibition toward LG formation than alkaline earth metal-loaded biochars. The catalytic effects followed the order of C-KCl ≈ C-NaCl > C-MgCl₂ > C-CaCl₂ for chloride-derived biochars and C-CH₃COOK ≈ C-CH₃COONa > C-(CH₃COO)₂Mg > C-(CH₃COO)₂Ca for acetate-derived biochars. Notably, C-(CH₃COO)₂Ca and C-(CH₃COO)₂Mg slightly promoted LGO formation, which was attributed to the synergistic effects of alkaline earth metal species, surface oxygen-containing functional groups and acetate-derived intermediates on dehydration reactions. Thermogravimetric and kinetic analyses further demonstrated that AAEM-loaded biochars reduced the apparent activation energy of cellulose pyrolysis and facilitated thermal decomposition. These findings provide new insights into the catalytic role of AAEM-loaded biochars and suggest a promising strategy for regulating anhydrosugar selectivity, particularly for the production of high-value LGO from biomass pyrolysis. Full article

Due to its abundant active sites, the bimetallic zeolite imidazole framework ZnCo-ZIF-67 exhibits excellent catalytic performance on the key oxidant ammonium perchlorate in composite solid propellants. In addition, carbon fiber has been proven to promote the combustion of propellants due to its high thermal conductivity efficiency. In order to integrate the advantages of both, this study designed and prepared a novel composite catalyst, ZnCo-ZIF-67/CF, by a co-precipitation method. The thermal decomposition test demonstrated that the ZnCo-ZIF-67/CF composite exhibited significant catalytic activity. When the addition amount was 5 wt%, the high-temperature decomposition peak temperature of AP decreased significantly from 424.3 °C to 337.2 °C, and the combustion process was also significantly accelerated. Furthermore, analysis of the products of thermal decomposition gases revealed a significant increase in the proportion of N₂O in the catalyzed products to 55.7%, whilst the proportion of high oxidation state nitrogen-containing oxides such as NO₂ and NOCl decreased. This finding suggests that the highly dispersed metal active sites in ZnCo-ZIF-67/CF synergistically promote the decomposition reaction pathway of AP, leading to enhanced N₂O generation. This study proposes a novel approach for the development of efficient and stable AP decomposition catalysts, which has positive significance for the regulation of the combustion performance of propellants. Full article

Reversible solid oxide cells (ReSOCs) represent one of the most promising electrochemical technologies for sustainable energy conversion and storage, yet their large-scale deployment remains constrained by electrode materials capable of sustaining stable performance under alternating oxidizing and reducing conditions. Reversible solid oxide cells require electrode materials that combine phase stability, chemical compatibility, redox tolerance and a microstructure suitable for gas transport and surface reactions. However, the relationships among cation composition, thermal processing, phase formation and local chemical homogeneity remain insufficiently understood, particularly for compositionally complex perovskite-related oxides. In this work, this problem was addressed through a comparative physicochemical screening of three candidate electrode materials synthesized by a simple co-precipitation route: two co-doped lanthanum ferrites, (La_0.8Sr_1.2) (Fe_0.9Co_0.1)O_6+δ (LSFC) and (La_0.8Ca_1.2) (Fe_0.9Co_0.1)O_6+δ (LCFC), and one high-entropy praseodymium nickelate, Pr(Ba_0.8Ca_0.2)(Fe_0.2Co_0.2Ni_0.2Cu_0.2Zn_0.2)₂O_6+δ (PBC-HEO). DTA–TG analysis was used to determine the thermal decomposition and crystallization ranges of the precipitated precursors. Phase evolution as a function of calcination temperature was investigated by X-ray diffraction, while Raman and FTIR spectroscopy were employed to examine the local metal–oxygen environment and structural disorder. Raman spectroscopy confirmed the formation of perovskite-type metal–oxygen frameworks in all samples and revealed distinct redistributions of spectral weight between apical/equatorial (or symmetry-related) BO₆ stretching sub-modes and bending/tilting modes, reflecting different local defect-chemical mechanisms associated with A-site doping (Sr vs. Ca) in the Ruddlesden–Popper ferrites and B-site multi-cation occupancy in the double-perovskite PBC-HEO. Bulk and local elemental compositions were assessed by ICP-MS and SEM-EDS, respectively, and SEM was used to compare particle morphology and porosity. SEM-EDS analysis showed that PBC-HEO developed the most open and interconnected microstructure among the investigated powders, although accompanied by residual compositional heterogeneity. This morphology may favor gas accessibility; however, its effective impact on electrocatalytic performance requires dedicated surface area, porosimetry, electrical, and electrochemical measurements. LSFC formed a single major Ruddlesden–Popper phase only after high-temperature calcination, whereas LCFC retained calcium-containing secondary phases. PBC-HEO developed a major perovskite-related phase at 700 °C, accompanied by minor Zn-rich segregation. Under the selected processing conditions, PBC-HEO retained the finest and most interconnected porous microstructure, although it also displayed the highest local compositional heterogeneity. These results demonstrate that cation selection and thermal history jointly control phase stability, local disorder and microstructure, providing a basis for the subsequent electrochemical evaluation and optimization of perovskite-related ReSOC electrode materials. Full article

This study investigates the high-temperature pyrolysis pathways and product distribution of the battery immersion coolant HFE-7300 (C₇H₃F₁₃O) within a simulated thermal runaway environment. Using a tube furnace system combined with GC-MS analysis across a temperature range of 300–800 °C (residence time of 3 s), the thermal stability and cracking evolution were evaluated. Experimentally, HFE-7300 exhibits low initial decomposition at 400 °C with a pyrolysis rate of 5.84%, which rapidly scales up to 48.72% at 500 °C, and reaches a near-complete degradation of 98.46% at 800 °C. Qualitative product characterization identified C₂H₄, C₂F₄, C₃F₆ C₄F₈, and C₅H₃F₉O as the primary species evolved. To map the micro-scale degradation trajectories, a reaction network comprising 12 elementary pathways was constructed via density functional theory (DFT) calculations at the B3LYP/6-311+G(d,p) level. Using the TST method, we calculated the reaction rate constants for the main decomposition pathways. Analysis reveals that the C4–C5 bond scission pathway (R6) serves as the predominant initial decomposition channel, yielding C₅H₃F₉O and CF₂=CF₂ as the definitive primary products. These findings provide baseline thermodynamic data and critical safety insights for the engineering design of immersion-cooled battery thermal management systems. Full article

Explosive detonation is a high-speed and high-energy chemical-physical transformation process that rapidly generates high-temperature and high-pressure gases as well as shock waves. These energies are released intensely in a short time, exhibiting extremely strong destructive power. When these high-temperature and high-pressure gases and shock waves act on the surface of combustibles, they can instantly peel off the hot core on the surface, disrupting the conditions necessary for sustaining the combustion reaction and thereby achieving a fire-extinguishing effect. However, to attain this application goal, it is essential to select explosive materials with both high energy density and low sensitivity. In this study, DFTB-MD (Density Functional Tight-Binding Molecular Dynamics) and DFT (Density Functional Theory) methods were employed to systematically investigate the thermal decomposition process of benzotrifuroxan (BTF)/1,3,5-trinitrobenzene (TNB) cocrystal nanoparticles under high-temperature conditions. Our simulations reveal, for the first time, that the thermal decomposition mechanism of BTF/TNB cocrystal nanoparticles is strongly size-dependent: the 1.8 nm particles exhibit earlier ring-opening of BTF due to the higher surface-to-volume ratio, while the 2.2 nm particles show superior structural stability and lower molecular diffusivity. Meanwhile, increasing temperature from 2100 K to 2400 K shifts the dominant initial decomposition pathway from C–NO₂ cleavage in TNB to ring rupture in BTF. These findings provide atomic-scale theoretical insights into the design and application of BTF/TNB cocrystal nanoparticles for explosion-based fire suppression. Full article

This work focuses on the combustion characteristics and kinetics of three building timber organic solid wastes (BTOSW)—China fir, Eucalyptus wood, and Pine wood—aiming to provide theoretical and data support for the thermal conversion and energy utilization of construction-derived woody biomass. Thermogravimetric analysis (TGA) reveals that all three materials exhibit two-stage combustion behavior: volatile combustion at low temperatures (<320 °C) and char combustion at high temperatures (320–500 °C). Increasing the heating rate shifts the decomposition peaks to higher temperature zones, reflecting the combined effects of thermal lag and shortened reaction time. Kinetic analysis shows that the correlation coefficients (R²) calculated by different models are all greater than 0.97, with the first-order chemical reaction model (O1) demonstrating the highest goodness-of-fit for Pine wood (R² = 1.000) and Eucalyptus wood (R² = 0.995), indicating that homogeneous chemical reactions dominate the combustion process. The initial combustion temperatures of China fir, Eucalyptus wood, and Pine wood are 256 °C, 262 °C, and 270.9 °C, respectively, with flammability indices of 1.08, 1.46, and 1.15 and comprehensive combustion characteristic indices of 2.71 × 10⁻², 1.26 × 10⁻², and 1.75 × 10⁻² °C⁻²min⁻¹, respectively. This work provides important theoretical support for both the energy utilization of timber-framed buildings waste and the fire protection design and flame retardancy of timber-framed buildings, contributing to the development of scientific fire prevention measures and the preservation of this architectural heritage. Full article

This experiment investigated changes in the key parameters of explosion pressure peak (P_max) and pressure rising rate peak ((dP/dt)_max) and flame propagation characteristics of wood dust explosion (pine, cypress and poplar dusts) under different wood dust diameters and concentrations using a 20 L spherical explosion apparatus. Combined with thermogravimetric analysis and Fourier transform infrared spectroscopy, the pyrolysis behavior of different wood dusts and the generation mechanism of gas-phase flammable products were elucidated. The results indicate that the type, wood dust diameter and concentration of dust had a great impact on the severity of explosion. As the dust diameter decreased, P_max and (dP/dt)_max both showed a trend of first increasing and then decreasing. Among them, the explosion pressure and K_st value of 300-mesh poplar wood were the highest, reaching 0.72 MPa and 11.6 MPa·m/s. The flame propagation characteristics were comprehensively influenced by dust morphology, volatile matter content and concentration. Among them, the peak height of flame propagation and its instantaneous velocity were obviously higher for poplar and pine wood dusts than those of cypress wood due to the high carbon and volatile matter contents. The overall quality loss rate of poplar dust in the thermogravimetric experiment was the highest, while its pyrolysis reaction rate was also the highest. The mass loss rate of 140-mesh poplar wood reached 90.5%, and the thermal decomposition reaction rate reached 19.48%/min. The large number of alkanes, aldehydes and ketones, as well as gases such as CO and CO₂ generated during the pyrolysis, provided the material basis for the chain reaction of a dust explosion. This study systematically elucidated the differences in explosion parameters, flame propagation behavior, and pyrolysis processes of different wood dust, thus providing theoretical support for their explosion risk assessment and safety protection. Full article

Porous microspheres based on 1,4-(dimethacryloyloxymethyl)naphthalene (DMN) and trimethylolpropane trimethacrylate (TRIM) were obtained by suspension–emulsion polymerization in the presence of toluene as a porogenic diluent. The obtained copolymers were subsequently modified using tetrachloromethane in the presence of anhydrous AlCl₃ via a Friedel–Crafts-type reaction. The influence of monomer composition and post-polymerization modification on the porous structure parameters and thermal stability of the materials was investigated. The synthesized copolymers exhibited well-developed porous structures with surface areas ranging from 368 to 494 m²/g. Increasing the TRIM content resulted in higher crosslinking density, earlier phase separation during polymerization, and formation of a finer porous architecture characterized by increased surface area and lower pore diameters. Chemical modification caused moderate and composition-dependent changes in the porous structure while preserving the mesoporous character of the materials. The highly crosslinked copolymers demonstrated the greatest structural stability during modification. Thermogravimetric analysis performed in helium revealed high thermal resistance of both parent and modified copolymers. The degradation process proceeded in two main stages characteristic of highly crosslinked methacrylate networks. Increasing TRIM content improved resistance toward advanced thermal decomposition, increasing the T_50% values up to 415 °C. Post-polymerization modification slightly decreased the temperature of the second degradation stage, probably due to the introduction of thermally less stable chlorinated fragments, while simultaneously increasing char residue formation. The synthesized materials were also evaluated as stationary phases for gas chromatography. Owing to their high thermal stability and the presence of polar ester functionalities, the copolymers enabled efficient separation of aliphatic alcohols at elevated temperatures. The obtained results demonstrate that porous poly(DMN-co-TRIM) microspheres constitute promising thermally stable materials with tunable porous structure and potential applications in chromatographic separation techniques. Full article

Thermal runaway in electric vehicle power battery packs is a key risk in fire prevention and control for electric transportation. Its triggering, propagation, and failure modes are jointly affected by external thermal abuse, material insulation performance, and side reactions inside cells. To identify the temperature response and fire risk of power battery packs under different thermal abuse intensities, this study established a three-dimensional multiphysics thermal runaway simulation model in COMSOL Multiphysics 6.1, coupling solid heat transfer, electrochemical heat generation, and side-reaction heat release. A semi-quantitative risk ranking was then performed using failure mode, effects, and criticality analysis (FMECA). The model considered the low-temperature safe conditions, 120 °C, 140 °C, and 170 °C, as the main ambient temperature conditions, while also analyzing the effects of the heat transfer coefficient on trigger time and peak temperature. The results show that, under the low-temperature safe condition and the 120 °C condition, the battery module mainly exhibits slow heating and does not undergo thermal runaway. Based on the side-reaction characteristics, the temperature near 125 °C can be used as a risk warning threshold for thermal runaway. At 140 °C, the side-reaction heat source increases markedly, and the system enters the thermal runaway risk region. Because the trigger time is strongly affected by the heat transfer coefficient and monitoring position, this condition is interpreted only as a risk-acceleration stage under critical thermal abuse. Approximately 167 °C can be regarded as the critical threshold for irreversible thermal runaway. Under severe thermal abuse at 170 °C, rapid intensification of internal side reactions increases the peak module temperature to 375–385 °C. Temperature field evolution shows that heat is transferred mainly from the exterior to the interior before thermal runaway, forming an outside-high- and inside-low-temperature distribution. After the runaway stage begins, heat release from internal cell side reactions becomes dominant, and the high-temperature region concentrates inside the module, producing a gradient reversal with a higher internal temperature. The FMECA results show that the positive electrode–electrolyte reaction has the highest RPN, with a value of 405. Accelerated SEI decomposition and the negative electrode–electrolyte reaction also form key risk links in the chain heat-release pathway. This study provides a reference for thermal management, fire barrier design, and fire risk classification of power battery packs. Full article

In this study, novel and stable cellulose-based oleogels with tunable rheological properties were successfully developed for lubrication applications via cross-linking reactions of epoxidized soybean oil (ESO), microcrystalline cellulose (MCC), and isocyanate. This cross-linking strategy not only overcomes the incompatibility issue arising from the polarity difference between MCC and ESO but also enables precise control over the oleogels’ rheological behavior by tailoring the cross-linking density. The resulting oleogels exhibit excellent thermal stability, with an initial decomposition temperature (T_5%) of approximately 300 °C. Furthermore, oxidation resistance is significantly enhanced with increasing cross-linking density, resulting in a substantial increase in the oxidation induction time (OIT) from 5 to 79 min at 210 °C. Rheological characterization reveals that the oleogels exhibit typical shear-thinning and thixotropic behavior. The plateau modulus ($G_N^0$) exhibits a positive correlation with cross-linking density, accompanied by a simultaneous improvement in structural recovery ability. Tribological tests show that the friction coefficient increases with the cross-linking degree, while four-ball tests indicate that the extreme-pressure load-carrying capacity is governed mainly by the nature of the base oil in addition to the cross-linking density of the gel network. This work provides a promising strategy for the development of high-performance and customizable bio-based lubricating materials. Full article

Monnex has become the most efficient dry powder extinguishing agent due to its unique fire extinguishing mechanism—the “burning fragmentation” phenomenon. To study the fire extinguishing mechanism of Monnex in detail and elucidate the process of its “burning fragmentation” phenomenon, we have examined the microstructure changes and compositions of Monnex powder during its thermal decomposition process. The results indicate that Monnex undergoes complex iterative reactions and produces explosive intermediates (NH₄NO₃, KCN, and KN₃) when entering the fire. Upon reaching the temperature of 240 °C, the explosive substance is completely pyrolyzed and undergoes a mini- burning fragmentation, resulting in the decomposition of Monnex powder into particles and the release of a large amount of inert gases and free radicals. This is the reason why Monnex has become an optimal dry powder. Toxic substances KCN and KOCN were found during the whole pyrolysis process, so personal protection should be paid attention to in practical applications. Our research not only improves the understanding of the Monnex fire extinguisher, but also provides important scientific evidence for the development of fire extinguishing technologies and environmentally friendly fire protection materials. Full article

This study investigates how O₂ concentration affects the combustion performance and kinetic response of Changji and Fushun oil shales under CO₂-based oxy-fuel atmospheres. Coupled TGA–DSC–MS analysis was performed to characterize thermal decomposition, heat release and absorption, gaseous product evolution, and apparent kinetic parameters. The results show that raising the O₂ concentration facilitates oil shale combustion. The TG–DTG and heat flow profiles move to lower-temperature regions as O₂ concentration increases. At 20 °C·min⁻¹, increasing the O₂ concentration from 35% to 100% reduced T_p1 and T_p2 from 357.3 and 519.7 °C to 331.2 and 491.5 °C for CJ oil shale, and from 352.3 and 484.0 °C to 326.6 and 429.7 °C for FS oil shale, respectively. These shifts were accompanied by decreases in ignition and burnout temperatures and an increase in the comprehensive combustion index. Fushun oil shale shows a more concentrated main mass-loss and heat-release region than Changji oil shale. It also exhibits lower ignition and burnout temperatures, indicating stronger overall combustion reactivity. By contrast, Changji oil shale displays more evident mass loss and thermal responses at high temperatures, suggesting a greater contribution from carbonate mineral decomposition in the later reaction stage. MS results further show that CO₂, H₂O, SO₂, and NO₂ release mainly occurs within 300–600 °C. Their release peaks shift toward lower temperatures as the O₂ concentration increases, indicating that oxygen-enriched atmospheres promote the oxidative conversion of organic carbon, hydrogen-containing structures, and S- and N-containing functional groups. The Vyazovkin nonlinear iso-conversional analysis provides conversion-dependent apparent activation energies rather than a single global kinetic parameter. The substantial variation in E_α with conversion highlights the overlapping and multi-stage nature of oil shale combustion. When the O₂ concentration is raised from 21% to 75%, E_α generally follows an upward trend; under pure O₂, however, it drops sharply. This non-monotonic variation suggests that O₂ concentration changes not only the combustion rate but also the dominant reaction routes at different conversion stages. These findings provide experimental support for selecting suitable oxy-fuel combustion conditions and improving the clean and efficient utilization of oil shale. Full article

Red blood cells (RBCs) are the most abundant cells in peripheral blood and perform critical functions including oxygen and carbon dioxide transport, acid base buffering, regulation of hemorheology, and modulation of immune signaling. Due to their high content of hemoglobin and labile iron, prolonged exposure to high oxygen tension, membrane enrichment with polyunsaturated fatty acids, and the absence of both nucleus and mitochondria, mature RBCs have limited capacity for damage repair and protein re-synthesis, making them highly susceptible to attack by reactive oxygen species (ROS) and reactive nitrogen species (RNS). Hydrogen peroxide (H₂O₂) and 2,2′-azobis(2-methylpropionamidine) dihydrochloride (AAPH) are the two most commonly used inducers in the in vitro models of RBC oxidative injury: H₂O₂ primarily generates hydroxyl radicals via hemoglobin/ferrous ion-dependent Fenton reactions, simulating acute oxidative stress. AAPH releases peroxyl radicals upon thermal decomposition, mimicking persistent lipid peroxidation in cell membranes. Curcumin, a representative polyphenolic compound derived from turmeric, exerts multiple effects including free radical scavenging, metal ion chelation, membrane stabilization, anti-inflammatory activity, and regulation of redox homeostasis. This review systematically summarizes the pathological basis of RBC oxidative damage and the protective effects of curcumin on membrane systems, antioxidant defenses, morphology, and function, based on the core evidence chain “H₂O₂/AAPH—RBCs—curcumin”, integrating recent experimental findings on H₂O₂, AAPH, blood storage-induced injury, and curcumin formulations. It emphasizes that mature RBCs lack nuclei and mitochondria, and therefore mechanisms such as Nrf2/ARE signaling, HO-1 induction, mitochondrial apoptosis, caspase cascades, and inflammasome activation should not be directly equated with transcriptional regulatory pathways within mature RBCs, but rather interpreted as indirect evidence originating from nucleated cells, erythroid progenitors, or the blood microenvironment. The article further proposes that future research should focus on standardized RBC models, physiologically relevant dosages, nanodelivery systems, and translational applications in blood storage, to facilitate the transition of curcumin’s in vitro antioxidant evidence into clinical transfusion medicine and precision nutritional interventions. Full article

Hydrophobic silica aerogels are widely used as thermal-insulation materials, but the thermal decomposition of their organic surface groups may affect their stability and safety during high-temperature service. In this study, ambient-pressure-dried silica aerogels modified with trimethylsilyl, dimethylsilyl, and methylsilyl groups were prepared and denoted as TSA, DSA, and MSA, respectively, to clarify how the degree of methyl substitution in the surface modifier controls the pyrolysis behavior of hydrophobic silica aerogels. Thermogravimetric analysis at different heating rates was combined with TG-FTIR, a model-free kinetic analysis, a model-fitting analysis and thermodynamic calculation. With decreasing methyl substitution from TSA to MSA, the aerogel framework became denser, the specific surface area decreased, and the contribution of solid-phase heat transfer increased slightly. The main pyrolysis process occurred at 250–800 °C and involved multiple overlapping reactions. The average activation energies of TSA, DSA, and MSA were 241.4, 246.6, and 285.5 kJ/mol according to the Kissinger–Akahira–Sunose (KAS) method and 243.0, 248.2, and 289.0 kJ/mol according to the Flynn–Wall–Ozawa (FWO) method, respectively. The higher activation energy of MSA indicates that the more condensed silica-rich framework and lower organic methyl content improves its resistance to the main degradation process. The model-fitting analysis further suggested an A1/2 mechanism for TSA and A2/5 mechanisms for DSA and MSA. TG-FTIR further confirmed the evolution of CO₂, H₂O, CH₄, and C₂H₄ and revealed distinct gas-release behaviors among the three samples. These results demonstrate that the surface methyl-substitution structure governs the balance between hydrophobic modification, pore-structure preservation, pyrolysis resistance, and volatile-product release, providing a basis for selecting surface modifiers for thermally stable silica-aerogel insulation materials under oxygen-limited high-temperature conditions. Full article